TABLE 2.
Growth and virulence of P. aeruginosa PAO1 and its siderophore production mutants inoculated intramuscularly into immunosuppressed mice
| Inoculum
|
Count of viable bacteriaa at 16 hpi in:
|
Lethality in miceb at:
|
||||
|---|---|---|---|---|---|---|
| Strain | Log10 CFU | Muscles | Blood | 16 hpi | 24 hpi | 48 hpi |
| PAO1 | 6.32 | 9.28 ± 0.13 (2.96) | 4.46 ± 0.21 | 2/5 | 5/5 | 5/5 |
| PAD02 | 6.30 | 9.08 ± 0.09 (2.78) | 4.39 ± 0.44 | 0/5 | 5/5 | 5/5 |
| PAD06 | 6.42 | 9.19 ± 0.21 (2.77) | 3.84 ± 0.23c | 0/5 | 4/5 | 5/5 |
| PAD07 | 6.24 | 7.09 ± 0.06d (0.89)d | <2.00d | 0/5 | 0/5d | 0/5d |
Samples were collected from three mice per group at 16 hpi and were assayed for viable bacteria. Values are mean log10 CFU ± SDs in muscles or in 1 ml of blood. Values in parentheses represent bacterial growth, expressed as the mean of the increases in the count (each count in the group at 16 hpi minus the inoculum), in log10 CFU. SDs for mean increases in the counts are theoretically identical to those for mean counts at 16 hpi.
Number of dead mice/number of mice inoculated for observation of bacterial virulence.
Significantly different (P < 0.05) from value for PAO1-inoculated group as calculated by Student's t test (for means) or Fisher's exact probability test (for frequencies).
Significantly different (P < 0.01) from value for PAO1-inoculated group as calculated by Student's t test (for means) or Fisher's exact probability test (for frequencies).